Laboratoire d'Informatique de Grenoble Équipe Ingénierie de l'Interaction Humain-Machine

Équipe Ingénierie de l'Interaction

Precise Pointing Techniques for Handheld AR

Precise Pointing Techniques for Handheld AR

We propose two techniques that improve accuracy of pointing at physical objects for handheld Augmented Reality (AR). In handheld AR, pointing accuracy is limited by both touch input and camera viewpoint instability due to hand jitter. The design of our techniques is based on the relationship between the touch input space and two visual reference frames for on-screen content, namely the screen and the physical object that one is pointing at. The first technique is based on Shift, a touch-based pointing technique, and video freeze, in order to combine the two reference frames for precise pointing. Contrastingly -without freezing the video-, the second technique offers a precise mode with a cursor that is stabilized on the physical object and controlled with relative touch inputs on the screen. Our experimental results show that our techniques are more accurate than the baseline techniques, namely direct touch on the video and screen-centered crosshair pointing.

Follow-up study on the effect of registration jitter:
Handheld Augmented Reality relies on the registration of digital content on physical objects. Yet, the accuracy of this registration depends on environmental conditions. It is therefore important to study the impact of registration jitter on interaction and in particular on pointing at augmented objects where precision may be required. We present an experiment that compares the effect of registration jitter on the following two pointing techniques: (1) screen-centered crosshair pointing; and (2) relative pointing with a cursor bound to the physical object’s frame of reference and controlled by indirect relative touch strokes on the screen. The experiment considered both tablet and smartphone form factors. Results indicate that relative pointing in the frame of the physical object is less error prone and is less subject to registration jitter than screen-centered crosshair pointing.


Thomas Vincent, Laurence Nigay